Centralized Traffic Control (CTC) is a form of railway signaling that is similar to an air traffic tower at an airport. A central train dispatcher’s office controls traffic flow in sections of the rail system. It has is a control panel with a line-drawn illustration of the railroad track system. This lights up and allows the dispatcher to see where the trains are located within the territory. Large railroads like Norfolk & Western (now part of Norfolk Southern) had multiple dispatcher’s offices and dispatchers for each operating division. These offices are located near the busiest yards or stations. Prior to their use, train routing decisions had to be carried out by local signal operators or even the train crew.